Waltiier feld



Ni'rnn STATES ATENT rrrcno WALTHER FELD, OF HGNNINGEN-ON-THE-RHINE,GERMANY, ASSIGNOR TO THE AMERICAN SUGAR REFINING COMPANY, OF NEl/V YORK,N. Y.

PROCESS OF EXTRACTING SUGA'R.

SPECIFICATION forming part of Letters Patent No. 592,518 dated October26, 1897. Application filed August 13, 1896. Serial No. 603,195. (Nospecimens.)

To all whom it may concern:

Be it known that I, WALTHER FELD, a subject of the German Emperor,residing at Honningen-on-the-Rhine,of Rhine Province, German Empire,have invented certain new and useful Improvements in Processes ofExtracting Sugar from Molasses and other saccharine Liquors by the Useof Barium Hydroxisulfid, of which the following is a specification.

It has heretofore been proposed to extract sugar from molasses or othersacchariferous liquors or juices by the use of barium compounds obtainedfrom barium sulfid, (BaS.) The barium sulfid is obtained by thereduction of commercial heavy spar or barium sulfate with coal. It isthe fact that when barium sulfid is leached systematically with hotWater it gives a solution of barium hydroxisulfid, (BaS+I'I O:BaSHOH,) asubstance which is very soluble in hot water, but will crystallizeeasily from the solution if cooled down to ordinary atmospherictemperature. The authorities have not hitherto accepted this fact butfor the purposes of the present case the matter is not important,because any chemist may theoretically explain the chemical reactionsdiiferently, and can, as hereinafter illustrated, easily substituteother formulas for those herein given. In any event the practical resultwill be the same.

In the process of extracting sugar from molasses as heretofore practiceda solution supposedly of barium sulfid, but actually containing aboutthirty-five per cent. to forty per cent. of barium hydroxisulfid andhaving a temperature of about 145 Fahrenheit,is thor oughly mixed withmolasses or other sacchariferous liquor in such proportions that themixture will contain for each one hundred parts of sugar about onehundred and fifteen parts of barium hydroxisulfid. Theoretically this isabout five per cent. more barium hydroxisulfid than is necessary, but itis advisable to use a small excess, and if the molasses contains glucoseor invert sugar a proportionally larger amount must be added-thus forone part of glucose about one part of barium hydroxisulfid. This excessreacts upon the glucose and transforms it into barium compounds. By thereaction of the sugar the barium hydroxisulfid is split into bariumoxid, which by combining with the sugar forms insoluble bariumsaccharate, and into water and barium hydrosulfid, which remainsdissolved in the Waste lye, according to the formula:

This reaction takes place at all temperatures, but in order toaccelerate it and have a complete precipitation of the saccharate it isusual to heat the mixture above 140 Fahrenheit. -By filtration throughfilter-presses and washing with Water in the usual manner the bariumsaccharate is separated from the waste lye, which contains, besides theimpurities originally present in the molasses, the Whole quantityofbarium hydrosulfid formed by the process, the excess of bariumhydroxisulfid used, and in lesser quantity various barium salts formedby the reaction of the barium hydroxisulfid upon the glucose and otherimpurities of the molasses.

The present invention consists in thehereinafter-described method ofextracting sugar from molasses or other sacchariferous liquors by theuse of barium compounds in such manner as to effect the economicalrecovery of the barium and sulfur employed.

The present invention is a modification of that set forth in my pendingapplication, Serial No. 586,435, describing a method of so conductingthe extraction of sugar from molasses or other sacchariferous liquors bythe use of barium compounds as to insure the re covery of the barium andsulfur employed. In the process described in the said application thewaste lye remaining after the formation and removal of the bariumsaccharate therefrom is saturated with carbonic acid in order totransform all the sulfur present in it into hydrogen sulfid, which bysubsequent burning with air is made to yield sulfurous acid. In orderthat the hydrogen sulfid may easily be made to thus yield sulfurousacid, it is essential that the carbonic-acid gas employed shall containa high percentage of pure carbonic acid-as, say, thirty to forty percent. The necessity for using carbonic gas containing such a highpercentage of pure carbonic acid is, by-the present invention, avoidedby first treating the waste lye either with magnesium sulfate or withmagnesium sulfite, which, for the purposes of the present invention, arethe equivalents of each other, it'being, of course, understood that theyare used not only to set free the hydrogen sulfid from the waste lye,but also to furnish the sulfuric acid, which, by combination with thebarium present, will ultimately form either barium sulfate or bariumsulfite, according to which of the said magnesium salts is employed. Incarrying out the'process there is mixed with the Waste lye such quantityof the magnesium salt employed as will suffice to decompose the bariumcompounds present and transform the barium into barium sulfate or bariumsulfite, as the case may be. The magnesium salt may be either insolution or in the form of a solid salt. The magnesium salt having beenintroduced into the waste lye, the mixture is boiled until all thesulfur previously combined with the barium is set free in the form ofgaseous hydrogen sulfid, which is conducted off to a gasometer, whilethere is concurrently formed in the Waste lye insoluble barium sulfateor barium sulfite, as the case may be, and magnesium hydrate. Forillustration, if magnesium sulfite is employed the result will be asindicated in the following formula:

nesium sulfite, or with sulfuric acid, which.

will transform the magnesium carbonate into magnesium sulfate, while ineither case the carbonic acid is set free. The barium sulfite is thenseparated by the use of .the ordinary filter-press. The object of thesulfur-acid treatment is simply to transform the magnesium carbonateinto a salt-to wit, magnesium sulfate or magnesium sulfite-which isadapted for use in a repetition of the described process of extractingsugar from another lot of molasses or other sacchariferous liquor. As amatter of economy it is preferred to use sulfurou's acid, because thehydrogen sulfid which has been collected in the earlier stages of theprocess can with little cost be made to yield sulfurous acid by theordinary process of burning it with air in a'suitable chamber.

- The separation of the sugar from the barium saccharate is effected byheating it with a solution of magnesium sulfite or magnesium sulfate,thus forming an aqueous solution of sugar mixed with insoluble bariumsulfite or barium sulfate and magnesium hydrate. This mixture is thentreated with carbonic-acid gas until the magnesium hydrate istransformed into magnesium carbonate, which, together with the bariumsalts, is then separated by filter-presses. The remaining puresugarsolution is then evaporated in the usual way to obtain thecrystallizable sugar therefrom.

The barium salt and the magnesium carbonate arelthen mixed with waterand treated with a sulfur acid, and the magnesium carbonate is thustransformed into a soluble magnesium salt susceptible of use in arepetition of the described process. Finally the barium salts obtained,as described, from the waste lye and by the decomposition of the bariumsaccharate are mixed with coal and heated in a reverberatory furnace inthe usual manner, and are thus transformed into barium sulfid, which maybe again used, as herein set forth.

It will be perceived that for the purposes of the different steps in thepresent process, in which they are respectively employed magnesiumsulfate and magnesium sulfite are equivalents of each other, and alsothat sulfuric acid and sulfurous acid are equivalents of each other.

What is claimed as the invention is 1. In processes for extracting sugarfrom molasses or other sacchariferous liquors by the use of bariumcompounds, the method of recovering from the waste lye the sulfur introdneed in combination with barium, which consists in adding to thewastelye a sulfur salt of magnesium, then boiling the waste lye andcollecting the thereby-developed gaseous hydrogen sulfid, and burningthe same to sulfurous acid, substantially as described.

'2. In processes for extracting sugar from molasses or othersacchariferous liquors by the use of barium compounds the method ofrecovering the barium frointhe waste lye, which consists in firstboiling the waste lye with a sulfur salt of magnesium; secondly,saturating it with carbonic acid; thirdly, separating the resultingprecipitate from the solution by filter-presses; fourthly, mixing saidprecipitate with water; fifthly, saturating the resulting mixture with asulfur acid; sixthly, separating the resulting barium salt from saidmixture by filtration, and,finally, mixing such barium salt with coaland reducing it in a reverberatory furnace to barium sulfid,substantially as described.

3. In processes for extracting sugar from molasses or othersacchariferous liquors by the use of barium compounds, whereby bariumsaccharate is formed, the method of re covering the barium whichconsists in first heating the barium saccharate with a sulfur salt ofmagnesium; secondly, saturating it with carbonic acid; thirdly,separating the precipitate from the solution; fourthly, mixing saidprecipitate with Water fifthly, saturating the resulting mixture with asulfur acid; sixthly, separating the resulting barium salt from themixture, and, finally, mixing such barium salt with coal and reducing itin a reverberatory furnace to barium sulfid, substantially as described.

4. The process of extracting sugar from molasses or other sacchariferousliquors by the use of barium compounds, as herein described, whereby theconstituents of the compounds employed are recovered in suitable formfor repeated use, which consists in treating asaccharine liquor withbarium hydroxisulfid, thus forming barium saccharate; separating thebarium saccharate from the Waste lye; heating the barium saccharate witha sulfur salt of magnesium and treating it with carbonic acid;separating the resulting sulfur salt of barium and the resultingmagnesium carbonate from the remaining pure-sugar solution; heating thewaste lye With a sulfur salt of magnesium; collecting thethereby-developed hydrogen sulfid and burning it to sulfuric acid; thentreating the Waste lye with carbonic acid; separating the resultingmagnesium carbonate and sulfur salt of barium; treating said magnesiumcarbonate and. sulfur salt of barium with a sulfur acid, preferably Withthe sulfurous acid yielded by the burning of the hydrogen sulfid,thereby producing a soluble sulfur salt of magnesium; separating thesulfur salt of barium, and, finally, reducing the thus-obtained bariumsalts to barium sulfid, substantially as set forth.

In testimony whereof I have affixed my sig

